textproduct: Rapid City

KEY MESSAGES

- Elevated to near-critical fire weather conditions Wednesday and Thursday; a Fire Weather Watch is in effect Thursday.

- Cooler with rain/snow behind cold front late Thursday through Friday.

- Trending warmer Saturday through early next week.

DISCUSSION

(This Evening Through Tuesday) Issued at 1256 PM MDT Tue Apr 14 2026

Active southwesterly flow continues across the central US. Water vapor imagery shows a shortwave trough pushing through the Northern Plains and an upper low ejecting out of the Central Rockies along with an active southern stream as moisture streams into the Southern Plains. Surface low pressure is centered over southeastern NE with a weak gradient over the forecast area. Light showers/sprinkles continue across southwestern SD into south- central SD, although a dry boundary layer and lack of appreciable mid-level moisture will limit precipitation amounts. Showers will taper off this afternoon and early evening as subsidence overspreads the region.

Warmer and dry tomorrow with temperatures in the upper 60s to upper 70s across the plains. Elevated to near-critical fire weather conditions are expected with RH falling into the teens to low 20s, particularly portions of NE WY and SW SD, although there is some uncertainty regarding boundary layer winds/if frequent gusts > 25 mph will develop. Even warmer (along and south of I90 in SD) and drier Thursday ahead of a cold front with critical conditions possible; a Fire Weather Watch is in effect from the Weston County plains through southern SD.

Cold front arrives Thursday evening bringing cooler air and potential for rain and snow. Upper trough will eject out of the Central Rockies, although recent guidance shows split flow developing. Pacific moisture advects into the region ahead of this trough, although appreciable moisture is lacking (precipitable water values ~100-125% of normal). Best chance of measurable precipitation across NE WY and the northern Black Hills (NBM prob QPF >0.25" ~30-55%).

Warm air advection returns Saturday with temperatures trending warmer through the weekend into early next week with elevated fire weather conditions expected.

AVIATION

(For the 18Z TAFS Through 18Z Thursday) Issued At 1127 AM MDT Wed Apr 15 2026

VFR conditions are expected through 16/15z. After 16/15z, a cold front will enter northeastern WY/northwestern SD with gusty northwest winds behind it. Toward the end of the forecast period, MVFR/IFR conditions may develop north/west of KGCC.

FIRE WEATHER

Issued At 509 AM MDT Wed Apr 15 2026

Elevated fire weather conditions expected today across much of the area as RH falls into the teens to low 20s. Best overlap of low RH and stronger winds forecast across southern Campbell and Weston Counties in WY through southwestern SD. Conditions should remain below thresholds for any fire weather highlights today.

A Fire Weather Watch is in effect Thursday for the Weston County plains through southern SD as stronger southwest winds will develop ahead of a cold front. Daytime minimum RH will fall as low as 12-14 percent Thursday. Mid-level clouds ahead of the front and spotty high-based showers may complicate things Thursday by keeping temperatures a bit cooler and RH higher. However, plan for at least elevated to near-critical conditions Thursday.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning from noon MDT /1 PM CDT/ to 7 PM MDT /8 PM CDT/ Thursday for SDZ321-322-325-326-332>335. WY...Red Flag Warning from noon to 7 PM MDT Thursday for WYZ317.